Air conditioner

Abstract

An air conditioner (2) that performs air conditioning control is provided with: one or more switching elements included in at least one power converter among one or more power converters that perform power conversion; a waveform shape changing unit capable of changing the waveform shape of the switching waveform of the switching element; operation state detection units (501-505) that detect the operation state of the air conditioner (2); and a waveform shape control signal output unit (420) that outputs a control signal when the switching waveform of the switching element is changed by the waveform shape changing unit in accordance with the operating state.

Description

Technical Field

[0001] The present disclosure relates to an air conditioner that performs air conditioning control. Background Art

[0002] In the past, in power converters such as inverters and converters mounted on air conditioners, gate resistors with different gate resistance values ​​are switched to connect to switching elements to change the switching speed of the switching elements. For example, Patent Document 1 discloses the following technology: in an inverter control device having an inverter main circuit with a plurality of switching elements, when changing the gate drive waveform of the switching element, a switch is used to switch the gate resistor connected to the switching element to a gate resistor with a different gate resistance value.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-200042 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The inverter control device described in Patent Document 1 is applied to an air conditioner, and by changing the switching speed of a switching element, an operation is performed that takes into account both noise and loss generated according to the operating state of the air conditioner. However, although the inverter control device described in Patent Document 1 switches according to the gate resistance value of the gate resistor in order to change the switching speed of the switching element, the number of gate resistance values ​​is limited. Therefore, the inverter control device described in Patent Document 1 has the following problem: sometimes the switching speed of the switching element cannot be optimal according to the operating state of the air conditioner, and the generation of noise and loss cannot be controlled to a desired state.

[0008] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to obtain an air conditioner capable of controlling the generation of noise and loss according to an operating state.

[0009] Means used to solve problems

[0010] In order to solve the above problems and achieve the purpose, the present invention is an air conditioner for air conditioning control. The air conditioner comprises: one or more switching elements, which are included in at least one of the one or more power converters for power conversion; a waveform shape changing unit, which can change the waveform shape of the switching waveform of the switching element; an operating state detection unit, which detects the operating state of the air conditioner; and a waveform shape control signal output unit, which outputs a control signal when the switching waveform of the switching element is changed by the waveform shape changing unit according to the operating state.

[0011] Effects of the Invention

[0012] The air conditioner of the present disclosure has an effect of being able to control the generation of noise and loss according to the operating state. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram showing a configuration example of an air conditioner according to Embodiment 1.

[0014] Figure 2 This is a diagram showing an example of conduction Joule loss, on-current, and on-voltage when the switching speed of the switching element of the inverter is slowed down in the power conversion device of the air conditioner according to the first embodiment.

[0015] Figure 3 This is a diagram showing an example of the conduction Joule loss, the on-current, and the on-voltage when the switching speed of the switching element of the inverter is increased in the power conversion device of the air conditioner according to the first embodiment.

[0016] Figure 4 This is a diagram showing an example of the relationship between noise and loss generated in a general switching element.

[0017] Figure 5 FIG. 1 is a first diagram showing the effect obtained by changing the switching speed of the switching elements of the inverter in the power conversion device of the air conditioner according to the first embodiment.

[0018] Figure 6 FIG. 2 is a second diagram showing the effect obtained by changing the switching speed of the switching elements of the inverter in the power conversion device for the air conditioner according to the first embodiment.

[0019] Figure 7 This is a diagram showing a configuration example of a waveform shape changing unit of the power conversion device included in the air conditioner according to the first embodiment.

[0020] Figure 8 The first diagram shows the relationship between the gate current outputted from the waveform shape changing unit and the gate voltage indicating the rising speed of the switching element in the power conversion device included in the air conditioner according to the first embodiment.

[0021] Fig. 9 The second diagram shows the relationship between the gate current output by the waveform shape changing unit and the gate voltage indicating the rising speed of the switching element in the power conversion device included in the air conditioner according to the first embodiment.

[0022] Fig.10 FIG. 3 is a third diagram showing the relationship between the gate current outputted from the waveform shape changing unit and the gate voltage indicating the rising speed of the switching element in the power conversion device included in the air conditioner according to the first embodiment.

[0023] Fig.11This is a diagram showing an example of the relationship between a basic pulse output by a basic pulse generating unit and a gate current output by a waveform shape changing unit in the power conversion device included in the air conditioner according to the first embodiment.

[0024] Fig.12 This is a flowchart showing an operation of changing the waveform shape of the switching waveform of the switching element in the power conversion device included in the air conditioner according to the first embodiment.

[0025] Fig.13 This is a diagram showing an example of a hardware configuration for realizing a control unit included in the power conversion device of the air conditioner according to Embodiment 1.

[0026] Fig.14 This is a diagram showing a configuration example of an air conditioner according to Embodiment 2.

[0027] Fig.15 This is a first diagram showing a rectifying portion of an inverter included in a power conversion device for an air conditioner according to a second embodiment.

[0028] Fig.16 FIG. 2 is a second diagram showing a rectifying portion of an inverter included in the power conversion device of the air conditioner according to the second embodiment.

[0029] Fig.17 FIG. 3 is a third diagram showing a rectifying portion of an inverter included in the power conversion device of the air conditioner according to the second embodiment.

[0030] Fig.18 This is a diagram showing a configuration example of an air conditioner according to Embodiment 3.

[0031] Fig.19 This is a diagram showing a configuration example of an air conditioner according to Embodiment 5.

[0032] Fig. 20 This is a diagram showing a configuration example of a speed estimation device included in a power conversion device of an air conditioner according to a fifth embodiment.

[0033] Fig.21 This is a diagram showing a configuration example of an air conditioner according to Embodiment 6.

[0034] Fig. 22 As a comparative example, the diagram shows an example of each current and a capacitor voltage of the capacitor when the current output from the converter is smoothed by the capacitor and the current flowing to the inverter is made constant.

[0035] Fig.23 This is a diagram showing an example of each current and the capacitor voltage of the capacitor when the control unit of the power conversion device included in the air conditioner according to the sixth embodiment controls the operation of the inverter to reduce the current flowing to the capacitor.

[0036] Fig.24 This is a diagram showing a configuration example of an air conditioner according to Embodiment 7.

[0037] Fig.25 This is a diagram showing a configuration example of an air conditioner according to Embodiment 8. DETAILED DESCRIPTION

[0038] Hereinafter, an air conditioner according to an embodiment of the present disclosure will be described in detail based on the drawings.

[0039] Implementation method 1.

[0040] Figure 1 1 is a diagram showing a configuration example of an air conditioner 2 according to Embodiment 1. The air conditioner 2 that performs air conditioning control includes a power conversion device 1 and a motor 314. The power conversion device 1 is connected to a commercial power source 110 and the motor 314. The power conversion device 1 converts a first AC power having a power supply voltage Vs supplied from the commercial power source 110 into a second AC power having a desired amplitude and phase, and supplies the second AC power to the motor 314. The commercial power source 110 is connected to a power source 110 and a motor 314. Figure 1 The example is a single-phase AC power supply, but a three-phase AC power supply may also be used. The power conversion device 1 includes an operation state detection unit 501, a converter 130, a capacitor 210, an operation state detection unit 502, an inverter 310, an operation state detection unit 503, an operation state detection unit 504, an operation state detection unit 505, and a control unit 400.

[0041] The operating state detection unit 501 detects the operating state of the air conditioner 2. The operating state detection unit 501 detects, for example, the voltage value of the AC power of the power supply voltage Vs supplied from the commercial power supply 110 to the inverter 130, the current value of the AC power of the power supply voltage Vs supplied from the commercial power supply 110 to the inverter 130, and the like.

[0042] The inverter 130 is a power converter that converts AC power of a power supply voltage Vs supplied from a commercial power supply 110 into DC power. The inverter 130 includes rectifying elements 131 to 134, a reactor 135, a switching element 136, a freewheeling diode 137, a diode 138, and a drive circuit 150. The inverter 130 has a bridge circuit composed of rectifying elements 131 to 134, rectifies the first AC power of a power supply voltage Vs supplied from the commercial power supply 110, and outputs the rectified DC power by boosting the voltage. The drive circuit 150 generates a drive signal for actually driving the switching element 136 based on a basic pulse generated by a basic pulse generating unit 410 of a control unit 400 described later. The switching element 136 is, for example, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a bipolar transistor, etc., but is not limited thereto. In addition, the structure of the inverter 130 is not limited to Figure 1 Inverter 130 may also be configured by using a switching element to form one or more of the rectifying elements 131 to 134. Figure 1 In the power conversion device 1 of the first embodiment shown, the inverter 130 may have only a rectifying function and not a boosting function. In addition, when the commercial power supply 110 is a three-phase AC power supply, the inverter 130 is configured to include six rectifying elements.

[0043] The capacitor 210 is connected to the output end of the inverter 130, and smoothes the DC power converted by the inverter 130. The capacitor 210 is, for example, an electrolytic capacitor, a film capacitor, or the like.

[0044] The operating state detection unit 502 detects the operating state of the air conditioner 2. The operating state detection unit 502 detects, for example, the voltage value of the DC power supplied from the capacitor 210 to the inverter 310, and the like.

[0045] The inverter 310 is a power converter connected to both ends of the capacitor 210. The inverter 310 has switching elements 311a to 311f and freewheeling diodes 312a to 312f. The inverter 310 switches the switching elements 311a to 311f on and off under the control of the control unit 400, converts the power output from the converter 130 and the capacitor 210 into a second AC power having a desired amplitude and phase, that is, generates the second AC power, and outputs it to the motor 314. The switching elements 311a to 311f are, for example, IGBTs, MOSFETs, bipolar transistors, etc., but are not limited thereto. The circuit structure of the inverter 310 is a full-bridge circuit, a single-phase bridge circuit, a half-bridge circuit, etc., and is not particularly limited. In addition, in the present embodiment, the inverter 310 has a waveform shape changing unit 340 that can change the waveform shape of the switching waveform of the switching elements 311a to 311f. The waveform shape changing unit 340 can output two or more waveform shapes as the waveform shapes of the switching waveforms of the switching elements 311a to 311f. Figure 1 In the example of FIG. 3 , the waveform shape changing unit 340 is configured to be able to change the waveform shape of the switching waveform of the switching elements 311a to 311f, but it is configured to be able to change the waveform shape of the switching waveform of at least one of the switching elements 311a to 311f. In addition, the inverter 310 may also be configured to include the waveform shape changing unit 340 for each of the switching elements 311a to 311f. The detailed operation of the waveform shape changing unit 340 will be described later.

[0046] The operating state detection unit 503 detects the operating state of the air conditioner 2. The operating state detection unit 503 detects, for example, the voltage value of the second AC power supplied from the inverter 310 to the motor 314 as a load, the current value of the second AC power supplied from the inverter 310 to the motor 314 as a load, etc. The operating state detection unit 504 detects the operating state of the air conditioner 2. The operating state detection unit 504 detects, for example, the current value of the DC power supplied from the capacitor 210 to the inverter 310, etc. The operating state detection unit 505 detects the operating state of the air conditioner 2. The operating state detection unit 505 detects, for example, the current flowing through the switching elements 311b, 311d, and 311f, etc.

[0047] The control unit 400 obtains the operating state detected by the operating state detection units 501 to 505 from the operating state detection units 501 to 505, and controls the operation of the converter 130 and the inverter 310 based on the obtained operating state, specifically, controls the on and off of the switching element 136 of the converter 130, and controls the on and off of the switching elements 311a to 311f of the inverter 310. The control unit 400 includes a basic pulse generation unit 410 and a waveform shape control signal output unit 420.

[0048] The basic pulse generating unit 410 generates a basic pulse having a duty ratio corresponding to the operating state detected by the operating state detecting units 501 to 505 and used to control the operation of the switching element 136 of the converter 130. In addition, the basic pulse generating unit 410 generates a basic pulse having a duty ratio corresponding to the operating state detected by the operating state detecting units 501 to 505 and used to control the operation of the switching elements 311a to 311f of the inverter 310. The basic pulse is, for example, a PWM (Pulse Width Modulation) signal having a duty ratio corresponding to the operating state detected by the operating state detecting units 501 to 505. The basic pulse generating unit 410 outputs the basic pulse for controlling the operation of the switching element 136 of the converter 130 to the converter 130, and outputs the basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310 to the waveform shape control signal output unit 420.

[0049] The waveform shape control signal output unit 420 sets the waveform shape of the switching waveform of the switching elements 311a to 311f when the waveform shape change unit 340 of the inverter 310 changes the switching waveform of the switching elements 311a to 311f according to the operating state detected by the operating state detection units 501 to 505, and outputs a control signal indicating the set waveform shape. Specifically, the waveform shape control signal output unit 420 controls the magnitude of the drive signal output to the switching elements 311a to 311f and the timing of outputting the drive signal when the switching elements 311a to 311f are turned on and off based on the basic pulses generated by the basic pulse generation unit 410 for controlling the operation of the switching elements 311a to 311f of the inverter 310. The waveform shape control signal output unit 420 outputs the control signal for controlling the operation of the waveform shape change unit 340 to the waveform shape change unit 340. Alternatively, when the inverter 310 includes a waveform changer 340 for each switching element 311a to 311f, i.e., includes six waveform changers 340 , the control unit 400 may include a waveform control signal output unit 420 for each waveform changer 340 , i.e., includes six waveform control signal output units 420 .

[0050] In addition, Figure 1In the example, the control unit 400 obtains the operating status detected by the operating status detection units 501 to 505 from the operating status detection units 501 to 505, and controls the operation of the converter 130 and the inverter 310 based on the obtained operating status, but is not limited to this. The control unit 400 can control the operation of the converter 130 and the inverter 310 based on the operating status obtained from at least one of the operating status detection units 501 to 505. In the power conversion device 1, the operating status detection units 501 to 505 in the above example detect the voltage or current input to each structure of the power conversion device 1, the voltage or current output from each structure of the power conversion device 1, etc. as the operating status, but the detection object is not limited to this. In addition, the setting position of the operating status detection units 501 to 505 is not limited to Figure 1 The power conversion device 1 does not need to be in accordance with Figure 1 All operating state detection units 501 to 505 are configured in that way. As long as the operating state can be detected, the power conversion device 1 may also include an operating state detection unit at any position other than the position shown in the figure. Alternatively, the power conversion device 1 may use the noise generated by the power conversion device 1, the motor 314, etc., the loss generated by the power conversion device 1, the motor 314, etc., the temperature of each structure of the power conversion device 1, the motor 314, etc. as the operating state, and include an operating state detection unit at a position where these operating states can be detected. In addition, as the operating state of the air conditioner 2, the control unit 400 can use information such as the set temperature for the air conditioner 2, the heating, cooling, etc. operating mode of the air conditioner 2, etc. obtained from a remote controller not shown in the figure used by the user, etc.

[0051] In addition, the basic pulse generating unit 410 and the waveform shape control signal output unit 420 of the control unit 400 both operate based on the operating state obtained from the operating state detection units 501 to 505, so the functions of the basic pulse generating unit 410 and the waveform shape control signal output unit 420 can also be integrated into one structure.

[0052] The motor 314 is a load connected to the power conversion device 1. The motor 314 is, for example, a compressor motor for driving a compressor. The motor 314 rotates according to the amplitude and phase of the second AC power supplied from the inverter 310 to perform a compression action. For example, in the case where the compressor is a sealed compressor used in the air conditioner 2, the load torque of the motor 314 that drives the compressor is mostly regarded as a constant torque load. For the motor winding not shown in the figure, the motor 314 can be a Y connection, a Δ connection, or a specification that can switch between Y connection and Δ connection. In addition, the load connected to the power conversion device 1, i.e., the inverter 310, is not limited to the motor 314 for driving the compressor, and can also be a fan motor used in the air conditioner 2, etc. That is, the motor 314 is a compressor motor, a fan motor, etc.

[0053] In the present embodiment, the power conversion device 1 can change the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 through the waveform shape control signal output unit 420 and the waveform shape change unit 340. Specifically, the power conversion device 1 can change the switching speed, delay time, etc. of the switching elements 311a to 311f of the inverter 310.

[0054] Figure 2 This is a diagram showing an example of conduction Joule loss, on-current, and on-voltage when the switching speed of the switching elements 311 a to 311 f of the inverter 310 is slowed down in the power conversion device 1 of the air conditioner 2 according to the first embodiment. Figure 3 This is a diagram showing an example of conduction Joule loss, conduction current, and conduction voltage when the switching speed of the switching elements 311a to 311f of the inverter 310 is increased in the power conversion device 1 of the air conditioner 2 according to the first embodiment. Figure 2 and Figure 3 In the figure, A represents the conduction Joule loss, B represents the conduction current, and C represents the conduction voltage. Figure 2 and Figure 3 In the figure, the horizontal axis represents time. For example, the on-current is the current flowing through the switch element 311a, the on-voltage is the voltage applied to both ends of the switch element 311a, and the on-joule loss is obtained by multiplying the on-current and the on-voltage. However, the measurement object is not limited to the switch element 311a, and can also be other switch elements 311b to 311f. In addition, Figure 2 and Figure 3 The difference in characteristics caused by the switching speed of the switching elements 311a to 311f of the inverter 310 is shown, and the specific values ​​of "slow" and "fast" of the switching speed are not particularly limited. Figure 2 and Figure 3 As shown in , by slowing down the switching speed, the noise indicated by the peak value of the on-current of B decreases, but the loss indicated by the area of ​​the on-joule loss of A increases. Figure 2 and Figure 3 As shown, by increasing the switching speed, the noise represented by the peak value of the on-current of B increases, but the loss represented by the area of ​​the on-joule loss of A decreases. That is, in the switching elements 311a to 311f, the generated noise and loss are in a trade-off relationship.

[0055] In the power conversion device 1, the waveform shape changing unit 340 is constituted by a digital gate driver. Alternatively, in the power conversion device 1, the switching elements 311a to 311f of the inverter 310 and the waveform shape changing unit 340 are constituted by a digital gate driver module. Thus, the power conversion device 1 can change the switching speed of the switching elements 311a to 311f of the inverter 310 by changing the command value of the software without changing the hardware, and can control the noise and loss generated by the switching elements 311a to 311f to a desired state.

[0056] Figure 4 is a diagram showing an example of the relationship between noise and loss generated by a general switching element. As described above, the noise and loss generated by a switching element are in a trade-off relationship. Therefore, Figure 4 As shown, in a conventional switching element, by increasing the switching speed, the noise increases but the loss decreases, and by decreasing the switching speed, the noise decreases but the loss increases.

[0057] Figure 5 1 is a first diagram showing the effect obtained by changing the switching speed of the switching elements 311a to 311f of the inverter 310 in the power conversion device 1 of the air conditioner 2 according to the first embodiment. Regarding the power conversion device 1, even if it is operated within the noise range specified by the air conditioner 2, which is a product equipped with the power conversion device 1, when the load state of the motor 314 changes from a light load to a heavy load, as shown in FIG. Figure 5 As shown, the curve representing the characteristics of noise and loss generated by the switching elements 311a to 311f also shifts to the upper right, resulting in an increase in noise. That is, in the power conversion device 1, the heavier the load, the more the noise increases. Therefore, the power conversion device 1 can reduce the noise generated by the switching elements 311a to 311f by slowing down the switching speed of the switching elements 311a to 311f.

[0058] When the load state of the motor 314 changes from a light load to a heavy load, the waveform shape control signal output unit 420 changes the waveform shape of the switching waveform of the switching elements 311a to 311f so that the noise generated by the switching elements 311a to 311f satisfies the prescribed requirements. When the operating state is a light load operation less than a prescribed load, the waveform shape control signal output unit 420 changes the waveform shape of the switching waveform of the switching element 311a to suppress loss, and when the operating state is a heavy load operation greater than a prescribed load, the waveform shape of the switching waveform of the switching element 311a is changed to suppress noise.

[0059] Figure 6FIG. 2 is a diagram showing the effect obtained by changing the switching speed of the switching elements 311a to 311f of the inverter 310 in the power conversion device 1 of the air conditioner 2 according to the first embodiment. Specifically, the waveform shape changing unit 340 of the power conversion device 1 divides the on-period or off-period into two or more periods in one switching operation of the switching elements 311a to 311f, and changes the amplitude of the gate current or gate voltage for the switching elements 311a to 311f to different sizes in each of the divided periods. The power conversion device 1 is configured as follows: Figure 6 As shown in FIG. 1 , the switching waveforms of the switching elements 311a to 311f are optimized to obtain Figure 4 The characteristics of noise and loss generated by the switching elements 311a to 311f which cannot be obtained by conventional switching elements are shown.

[0060] Here, a description is given of the configuration of the waveform shape changing unit 340. Here, as an example, in order to simplify the description, a description is given of a case where the waveform shape changing unit 340 can change the waveform shape of the switching waveform of one switching element 311a. Figure 7 This is a diagram showing a configuration example of the waveform shape changing unit 340 of the power conversion device 1 included in the air conditioner 2 according to the first embodiment. Figure 7 This is also a diagram showing a configuration example of a digital gate driver module composed of a waveform shape changing unit 340 and a switching element 311a. Figure 1 As shown, the waveform shape changing unit 340 is included in the inverter 310, and the inverter 310 is a power converter including a switching element 311a. The waveform shape changing unit 340 includes n P-channel MOSFETs for conduction, namely PMOS (P-channel Metal Oxide Semiconductor), n PreDrivers for operating the n PMOS, n N-channel MOSFETs for cutoff, namely NMOS (N-channel Metal Oxide Semiconductor), and n PreDrivers for operating the n NMOS.

[0061] The waveform changing unit 340 is connected to the control power supply Vdd and the ground GND. The waveform changing unit 340 changes the number of PMOS or NMOS to be operated based on the control signal from the waveform control signal output unit 420, thereby making it possible to change the gate current I as the drive signal output to the switch element 311a during each period of the on period and the off period. GThe amplitude value of is changed to n types to adjust the switching speed of the switch element 311a. The more the waveform shape changer 340 increases the number of PMOS or NMOS in operation, the greater the gate current I output to the switch element 311a can be. G The greater the absolute value of the gate current I, the faster the switching speed of the switching element 311a can be. In addition, for the waveform shape changing unit 340, the more PMOS and NMOS are provided inside, the more finely the switching speed of the switching element 311a can be adjusted. G The faster the response to the increase or decrease of I, the finer the gate current I can be adjusted during one switching period. G The control signal from the waveform shape control signal output unit 420 can be either an analog signal or a digital signal as long as the number of PMOS or NMOS to be operated can be changed by the waveform shape change unit 340. Figure 7 In the example of FIG. 4 , m control signals are connected in parallel from the waveform shape control signal output unit 420 to the waveform shape changing unit 340. However, this is an example, and the number of control signals is not limited to m. The number of control signals may be a number that can indicate whether each PMOS and each NMOS can operate. If the control signal indicates a voltage or the like by an analog signal, the number may be 1.

[0062] Figure 8 1 is a graph showing the gate current I outputted by the waveform shape changing unit 340 in the power conversion device 1 included in the air conditioner 2 according to the first embodiment. G The gate voltage V G Figure 1 of the relationship. Fig. 9 1 is a graph showing the gate current I outputted by the waveform shape changing unit 340 in the power conversion device 1 included in the air conditioner 2 according to the first embodiment. G The gate voltage V G The second figure of the relationship. Figure 8 and Fig. 9 As shown in FIG. 1 , the waveform shape changing unit 340 increases the output gate current I G , the faster the gate voltage V G The higher the value, the faster the switching speed of the switching element 311a can be made. Figure 8 and Fig. 9 As shown in FIG. 1 , the waveform shape changing unit 340 decreases the output gate current I G , the more it can slow down the gate voltage V G The higher the value, the slower the switching speed of the switching element 311a can be. Figure 5As shown, the power conversion device 1 can reduce the output gate current I when it is desired to reduce the noise generated by the switching element 311a. G By slowing down the switching speed and reducing the loss caused by the switching element 311a, the output gate current I can be increased. G This makes the switching speed faster. In addition, Figure 8 and Fig. 9 The gate current I G and gate voltage V G The waveform is an ideal example, Figure 2 and Figure 3 As shown, in fact, the gate current I G It takes time for the current to reach a certain value.

[0063] Fig.10 1 is a graph showing the gate current I outputted by the waveform shape changing unit 340 in the power conversion device 1 included in the air conditioner 2 according to the first embodiment. G The gate voltage V G Figure 3 of the relationship. Fig.10 As shown, the waveform shape changing unit 340 can divide the conduction period and change the gate current I G That is, the waveform shape changing unit 340 can finely adjust the gate current I within one conduction period. G Therefore, the same gate current I as that output during the on-time is G Compared with the case of Figure 6 As shown, control is performed to reduce the noise generated by the switching element 311a and reduce the loss generated by the switching element 311a.

[0064] use Figures 8 to 10 , the on-period of the switch element 311a is described as an example, but the off-period of the switch element 311a is the same. Fig.11 1 and 2 show the relationship between the basic pulse output by the basic pulse generating unit 410 and the gate current I output by the waveform shape changing unit 340 in the power conversion device 1 included in the air conditioner 2 according to the first embodiment. G The following is an example of a relationship between . Fig.11 In the on-period of the switching element 311a, the waveform shape changing unit 340 controls the output gate current I G During the period of division, the gate current I with a large amplitude current Ig2 can be output at the beginning. G Then, the gate current I with a small amplitude Ig1 is output. G , it is also possible to output a gate current I with a small amplitude of current Ig1 at the beginning GThen, the gate current I with a large amplitude Ig2 is output. G Similarly, the waveform shape changing unit 340 changes the output gate current I during the off period of the switching element 311a. G During the period of division, the gate current I with a large amplitude of current -Ig2 can be output at the beginning G Then the gate current I with a small amplitude of -Ig1 is output. G , it is also possible to output a gate current I with a small amplitude of -Ig1 at the beginning G Then the gate current I with a large current amplitude -Ig2 is output. G .

[0065] Thus, the waveform shape changing unit 340 can divide at least one of the on-period and off-period of the switching element 311a into two or more periods based on the control signal output from the waveform shape control signal output unit 420, and change the gate current I G The amplitude of the gate current I is changed to a different size. In addition, the waveform shape changing unit 340 includes a plurality of transistors, and the number of transistors to be operated is changed based on the control signal output from the waveform shape control signal output unit 420, thereby being able to change the gate current I G Thus, the air conditioner 2 can change the noise and loss generated by the switching element 311a according to the operating state.

[0066] In addition, the waveform shape changing unit 340 can change the gate current I G The waveform shape changer 340 can change the switching waveform to a different waveform shape according to each switching cycle of the switching element 311a during the operation of the power conversion device 1. For example, the waveform shape changer 340 changes the waveform shape of the switching waveform of the switching element 311a during the rotation of at least one of the motors 314, i.e., the compressor motor, the fan motor, etc., provided in the air conditioner 2. In this case, the waveform shape control signal output unit 420 can change the waveform shape of the switching waveform of the switching element 311a with the same period as the switching cycle of the switching element 311a. The waveform shape control signal output unit 420 can also change the waveform shape of the switching waveform of the switching element 311a according to a period of a positive integer multiple of the switching cycle of the switching element 311a.

[0067] In addition, regarding the structure of the waveform shape changing unit 340, Figure 7The structure of the waveform shape changing unit 340 shown is an example and is not limited thereto. In this way, the waveform shape changing unit 340 can adjust the switching speed of the switching element 311a more finely by digital control based on multiple MOS (Metal Oxide Semiconductor) compared with the analog control of physically switching the gate resistance described in Patent Document 1. In addition, the waveform shape changing unit 340 can also use transistors other than MOS for the transistors used internally.

[0068] In the above example, the waveform shape changing unit 340 changes the number of PMOS or NMOS to be operated according to the acquired control signal, and changes the gate current I corresponding to the number of PMOS or NMOS to be operated. G The waveform shape changing unit 340 may also store the gate current I corresponding to the control signal in advance. G The gate current I is output according to the output pattern, i.e., waveform shape, corresponding to the acquired control signal. G In addition, the waveform shape changing unit 340 may also store in advance the control signal obtained in the past and the gate current I when the control signal was obtained in the past. G When the same control signal is obtained, the gate current I is output according to the stored output style, that is, the waveform shape. G The waveform shape changing unit 340 stores the gate current I corresponding to the control signal in advance. G The output style, i.e. waveform shape, can reduce the output gate current I G processing load.

[0069] In addition, Figure 7 In the example of FIG. 1 , the waveform shape changing unit 340 changes the gate current I G The waveform shape changing unit 340 can use the drive signal output to the switching element 311a as the gate voltage V G , by changing the gate voltage V G , similarly, the switching speed of the switching element 311a is adjusted to change the waveform shape of the switching waveform of the switching element 311a.

[0070] Thus, the waveform shape changing unit 340 can divide at least one of the on-period and off-period of the switching element 311a into two or more periods based on the control signal output from the waveform shape control signal output unit 420, and change the gate voltage V for the switching element 311a to V in each of the divided periods.G The amplitude of the waveform changer 340 is changed to a different size. In addition, the waveform changer 340 includes a plurality of transistors, and the number of transistors to be operated is changed based on the control signal output from the waveform control signal output unit 420, thereby being able to change the gate voltage V G Thus, the air conditioner 2 can change the noise and loss generated by the switching element 311a according to the operating state.

[0071] Fig.12 1 is a flowchart showing an operation of changing the waveform shape of the switching waveform of the switching elements 311a to 311f in the power conversion device 1 included in the air conditioner 2 according to the first embodiment. In the power conversion device 1, the basic pulse generation unit 410 generates a basic pulse for driving the switching elements 311a to 311f of the inverter 310 based on the operating state obtained from the operating state detection units 501 to 505 (step S1). In this way, in the control unit 400, the basic pulse generation unit 410 generates a basic pulse based on the operating state obtained from the operating state detection units 501 to 505, and determines the timing of turning on the switching elements 311a to 311f and the timing of turning off the switching elements 311a to 311f. The basic pulse generation unit 410 outputs the generated basic pulse to the waveform shape control signal output unit 420.

[0072] The waveform shape control signal output unit 420 sets a waveform shape for changing the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 based on the basic pulse obtained from the basic pulse generation unit 410 and the operating state obtained from the operating state detection units 501 to 505. In this way, in the control unit 400, the waveform shape control signal output unit 420 sets the waveform shape of the switching waveform of the timing of turning on the switching elements 311a to 311f and the timing of turning off the switching elements 311a to 311f determined by the basic pulse generation unit 410 based on the operating state obtained from the operating state detection units 501 to 505. The waveform shape control signal output unit 420 outputs a control signal that can change the size and output timing of the drive signal according to the set waveform shape to the waveform shape change unit 340 (step S2).

[0073] The waveform shape changing unit 340 changes the gate current I output to the switching elements 311a to 311f of the inverter 310 based on the control signal obtained from the waveform shape control signal output unit 420. G The waveform shape of the gate current I after the waveform shape change is changed, that is, the waveform shape of the switching waveform of the switching elements 311a to 311f (step S3). G The output is to the switching elements 311 a to 311 f of the inverter 310 .

[0074] Next, the hardware configuration of the control unit 400 included in the power conversion device 1 will be described. Fig.13 This is a diagram showing an example of a hardware configuration of a control unit 400 included in the power conversion device 1 that realizes the air conditioner 2 according to Embodiment 1. The control unit 400 is realized by a processor 91 and a memory 92 .

[0075] The processor 91 is a CPU (also called a Central Processing Unit, a central processing device, a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, a DSP (Digital Signal Processor), or a system LSI (Large Scale Integration). The memory 92 can be exemplified by a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (registered trademark) (Electrically EPROM). In addition, the memory 92 is not limited thereto, and may be a magnetic disk, an optical disk, a high-density disk, a mini disk, or a DVD (Digital Versatile Disc).

[0076] As described above, according to the present embodiment, in the power conversion device 1 of the air conditioner 2, the waveform shape control signal output unit 420 of the control unit 400 outputs a control signal for changing the switching waveform of the switching elements 311a to 311f through the waveform shape change unit 340 of the inverter 310 based on the operating state detected by the operating state detection units 501 to 505. The waveform shape change unit 340 of the inverter 310 changes the gate current I output to the switching elements 311a to 311f based on the control signal output from the waveform shape control signal output unit 420. G Or gate voltage V G , thereby changing the waveform shape of the switching waveform of the switching elements 311a to 311f. As a result, the air conditioner 2 can control the generation of noise and loss according to the operating state. In addition, the air conditioner 2 can suppress the increase in circuit scale and change the switching speed of the switching elements 311a to 311f. The air conditioner 2 finely adjusts the gate current I output to the switching elements 311a to 311f during one switching period. G Or gate voltage V G , it is possible to realize the waveform shape of the switching waveform of the switching elements 311 a to 311 f which cannot be realized in the method of Patent Document 1 and the like.

[0077] Implementation method 2.

[0078] In the first embodiment, the case where the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changed in the power conversion device 1 of the air conditioner 2 is described. In the second embodiment, the case where the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changed in the power conversion device 1 of the air conditioner 2 is described.

[0079] Fig.14 1 is a diagram showing a configuration example of an air conditioner 2 according to Embodiment 2. The air conditioner 2 includes a power conversion device 1 and a motor 314. The power conversion device 1 is connected to a commercial power supply 110 and the motor 314. The power conversion device 1 converts a first AC power of a power supply voltage Vs supplied from the commercial power supply 110 into a second AC power having a desired amplitude and phase, and supplies the second AC power to the motor 314. The power conversion device 1 includes an operation state detection unit 501, a converter 130, a capacitor 210, an operation state detection unit 502, an inverter 310, an operation state detection unit 503, an operation state detection unit 504, an operation state detection unit 505, and a control unit 400.

[0080] Fig.14 The power conversion device 1 of the second embodiment shown in FIG. Figure 1 In the power conversion device 1 of the first embodiment shown, the waveform shape changer 340 is deleted from the inverter 310 and the drive circuit 350 is added, and the drive circuit 150 is deleted from the converter 130 and the waveform shape changer 140 is added. Fig.14 The power conversion device 1 of the second embodiment shown in FIG. Figure 1 The power conversion device 1 of the illustrated embodiment 1 changes the output destinations of the basic pulse generator 410 and the waveform control signal output unit 420. Specifically, the basic pulse generator 410 outputs the basic pulse for controlling the operation of the switching element 136 of the converter 130 to the waveform control signal output unit 420, and outputs the basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310 to the inverter 310. In addition, the waveform control signal output unit 420 outputs the control signal for controlling the operation of the waveform changer 140 to the waveform changer 140.

[0081] In the inverter 310 , the drive circuit 350 generates a drive signal for actually driving the switching elements 311 a to 311 f based on the basic pulse generated by the basic pulse generating unit 410 of the control unit 400 .

[0082] In the present embodiment, the waveform control signal output unit 420 sets the waveform shape of the switching waveform of the switching element 136 when the switching waveform of the switching element 136 is changed by the waveform shape change unit 140 of the converter 130 according to the operating state detected by the operating state detection units 501 to 505, and outputs a control signal indicating the set waveform shape. Specifically, the waveform control signal output unit 420 controls the magnitude of the drive signal output to the switching element 136 and the timing of outputting the drive signal by the waveform shape change unit 140 of the converter 130 in order to actually drive the switching element 136 when the switching element 136 is turned on and off based on the basic pulse for controlling the operation of the switching element 136 of the converter 130 generated by the basic pulse generation unit 410. The waveform control signal output unit 420 outputs the control signal for controlling the operation of the waveform shape change unit 140 to the waveform shape change unit 140.

[0083] The waveform shape changing unit 140 can change the waveform shape of the switching waveform of the switching element 136. The waveform shape changing unit 140 can output two or more waveform shapes as the waveform shape of the switching waveform of the switching element 136. Fig.14 As shown in FIG. 1 , the waveform shape changing unit 140 is included in the inverter 130, and the inverter 130 is a power converter including a switching element 136. The structure of the waveform shape changing unit 140 is similar to Figure 7 The waveform shape changer 340 of the first embodiment shown in FIG. 1 has the same structure. That is, the waveform shape changer 140 and the switch element 136 are composed of one digital gate driver module. In addition, the waveform shape changer 140 may be similar to the waveform shape changer 340, but does not adjust the gate current I output to the switch element 136. G Instead, the gate voltage V output to the switching element 136 is adjusted. G as the driving signal.

[0084] Thus, the waveform shape changing unit 140 can divide at least one of the on-period and off-period of the switching element 136 into two or more periods based on the control signal output from the waveform shape control signal output unit 420, and change the gate current I G Or gate voltage V G The amplitude of the gate current I is changed to a different size. In addition, the waveform shape changing unit 140 includes a plurality of transistors, and the number of transistors to be operated is changed based on the control signal output from the waveform shape control signal output unit 420, thereby being able to change the gate current I G Or gate voltage V GThus, the power conversion device 1 can change the waveform shape of the switching waveform of the switching element 136 of the converter 130 by performing the same operation as in Embodiment 1 through the waveform shape control signal output unit 420 and the waveform shape change unit 140. In addition, the air conditioner 2 can change the noise and loss generated by the switching element 136 according to the operating state.

[0085] As described above, according to the present embodiment, in the power conversion device 1 of the air conditioner 2, the waveform shape control signal output unit 420 of the control unit 400 outputs a control signal for changing the switching waveform of the switching element 136 through the waveform shape change unit 140 of the inverter 130 according to the operating state detected by the operating state detection units 501 to 505. The waveform shape change unit 140 of the inverter 130 changes the gate current I output to the switching element 136 based on the control signal output from the waveform shape control signal output unit 420. G Or gate voltage V G , thereby changing the waveform shape of the switching waveform of the switching element 136. The waveform shape changing unit 140 can change the waveform shape of the switching waveform of the switching element 136 in the same way as the waveform shape changing unit 340 of the first embodiment changes the waveform shape of the switching waveform of the switching element 311a. Thus, the air conditioner 2 can control the generation of noise and loss according to the operating state. In addition, the air conditioner 2 can suppress the increase in circuit scale and change the switching speed of the switching element 136. The air conditioner 2 finely adjusts the gate current I output to the switching element 136 within one switching period. G Or gate voltage V G , it is possible to realize a waveform shape of the switching waveform of the switching element 136 which cannot be realized in the method of Patent Document 1 and the like.

[0086] In the present embodiment, the structure of the inverter 130 to which the waveform shape of the switching element is to be changed is not limited to Fig.14 Example. Fig.15 This is a first diagram showing a rectifying portion of the inverter 130 included in the power conversion device 1 of the air conditioner 2 according to the second embodiment. Fig.16 This is a second diagram showing a rectifying portion of the inverter 130 included in the power conversion device 1 of the air conditioner 2 according to the second embodiment. Fig.17 FIG. 3 is a diagram showing the rectifying portion of the inverter 130 included in the power conversion device 1 of the air conditioner 2 according to the second embodiment. Figures 15 to 17 In the figure, only Fig.14 The waveform shape changing unit 140 is omitted. Fig.15As shown in FIG. 1 , in a configuration where the converter 130 includes the reactor 135, the switching elements 136a to 136d, and the freewheeling diodes 137a to 137d, the waveform shape changing unit 140 may also change the waveform shape of the switching waveform of the switching elements 136a to 136d. Fig.16 As shown in FIG. 1 , in a configuration where the converter 130 includes a reactor 135, rectifier elements 131 to 134, a switch element 136, a flyback diode 137, and rectifier elements 131a to 134a, the waveform shape changer 140 may also change the waveform shape of the switching waveform of the switch element 136. Fig.17 As shown, in a structure in which the connected commercial power supply is a three-phase AC power supply 110a, and the converter 130 has reactors 135a~135c, rectifier elements 131a~131c, switching elements 136a~136c and freewheeling diodes 137a~137c, the waveform shape changer 140 can also change the waveform shape of the switching waveform of the switching elements 136a~136c.

[0087] Implementation method 3.

[0088] In the first embodiment, the case where the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changed in the power conversion device 1 of the air conditioner 2 is described. In the second embodiment, the case where the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changed in the power conversion device 1 of the air conditioner 2 is described. In the third embodiment, the case where the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changed in the power conversion device 1 of the air conditioner 2 and the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changed is described.

[0089] Fig.18 1 is a diagram showing a configuration example of an air conditioner 2 according to Embodiment 3. The air conditioner 2 includes a power conversion device 1 and a motor 314. The power conversion device 1 is connected to a commercial power supply 110 and the motor 314. The power conversion device 1 converts a first AC power of a power supply voltage Vs supplied from the commercial power supply 110 into a second AC power having a desired amplitude and phase, and supplies the second AC power to the motor 314. The power conversion device 1 includes an operation state detection unit 501, a converter 130, a capacitor 210, an operation state detection unit 502, an inverter 310, an operation state detection unit 503, an operation state detection unit 504, an operation state detection unit 505, and a control unit 400.

[0090] Fig.18 The power conversion device 1 of the third embodiment shown in FIG. Figure 1In the power conversion device 1 of the first embodiment shown, the drive circuit 150 is deleted from the inverter 130 and a waveform shape changing unit 140 is added. Fig.18 The power conversion device 1 of the third embodiment shown in FIG. Figure 1 The power conversion device 1 of the illustrated embodiment 1 changes the output destinations of the basic pulse generator 410 and the waveform control signal output unit 420. Specifically, the basic pulse generator 410 outputs the basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310 to the waveform control signal output unit 420, and outputs the basic pulse for controlling the operation of the switching element 136 of the converter 130 to the waveform control signal output unit 420. In addition, the waveform control signal output unit 420 outputs the control signal for controlling the operation of the waveform changer 340 to the waveform changer 340, and outputs the control signal for controlling the operation of the waveform changer 140 to the waveform changer 140.

[0091] In the present embodiment, the waveform shape control signal output unit 420 performs the operation described in the second embodiment together with the operation described in the first embodiment. In addition, in the present embodiment, the waveform shape change unit 340 performs the same operation as the operation described in the first embodiment, and the waveform shape change unit 140 performs the same operation as the operation described in the second embodiment. Thus, the power conversion device 1 can change the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 through the waveform shape control signal output unit 420 and the waveform shape change unit 340 by performing the same operation as the first embodiment. In addition, the power conversion device 1 can change the waveform shape of the switching waveform of the switching element 136 of the converter 130 through the waveform shape control signal output unit 420 and the waveform shape change unit 140 by performing the same operation as the second embodiment.

[0092] In addition, in the present embodiment, the power conversion device 1 can also perform the following control: at a certain timing, one of the waveform shape changers 140 and 340 changes the waveform shape of the switching waveform of the switching element, while the other does not change the waveform shape of the switching waveform of the switching element. In the present embodiment, the switching element as the object of the switching waveform of the switching element changed by the waveform shape changer 140 and 340 of the power conversion device 1 is one or more switching elements included in at least one of the one or more power converters that perform power conversion in the power conversion device 1.

[0093] As described above, according to the present embodiment, in the power conversion device 1 of the air conditioner 2, the waveform shape control signal output unit 420 of the control unit 400 outputs a control signal for changing the switching waveform of the switching elements 311a to 311f through the waveform shape change unit 340 of the inverter 310, and outputs a control signal for changing the switching waveform of the switching element 136 through the waveform shape change unit 140 of the converter 130, based on the operating state detected by the operating state detection units 501 to 505. The waveform shape change unit 340 of the inverter 310 changes the gate current I output to the switching elements 311a to 311f based on the control signal output from the waveform shape control signal output unit 420. G Or gate voltage V G , thereby changing the waveform shape of the switching waveform of the switching elements 311a to 311f. In addition, the waveform shape changing unit 140 of the inverter 130 changes the gate current I output to the switching element 136 based on the control signal output from the waveform shape control signal output unit 420. G Or gate voltage V G , thereby changing the waveform shape of the switching waveform of the switching element 136. As a result, the air conditioner 2 can control the generation of noise and loss according to the operating state. In addition, the air conditioner 2 can suppress the increase in circuit scale and change the switching speed of the switching elements 311a to 311f and the switching element 136. The air conditioner 2 finely adjusts the gate current I output to the switching elements 311a to 311f and the switching element 136 during one switching period. G Or gate voltage V G , it is possible to realize the waveform shapes of the switching waveforms of the switching elements 311 a to 311 f and the switching element 136 which cannot be realized in the method of Patent Document 1 and the like.

[0094] Implementation method 4.

[0095] In Embodiments 1 to 3, the power conversion device 1 of the air conditioner 2 changes the waveform shape of the switching waveform of the switching elements 311a to 311f and the switching element 136 according to the load state of the motor 314 and the like mounted on the air conditioner 2. In Embodiment 4, a method for determining the load state of the power conversion device 1 is described. Hereinafter, the power conversion device 1 of Embodiment 1 is specifically described as an example.

[0096] The operating state of the air conditioner 2 changes greatly depending on the operating state. For example, when the temperature difference between the user's set temperature, i.e., the user's desired temperature, and the current indoor temperature in the room that is the air conditioning control object is large, the load of the power conversion device 1 mounted on the air conditioner 2 becomes large. On the other hand, when the temperature difference between the user's desired temperature and the current indoor temperature is small, the load of the power conversion device 1 mounted on the air conditioner 2 becomes small.

[0097] Regarding the load state, the power conversion device 1 can detect the current flowing through each part, the voltage applied to each part, etc. based on the current value, such as the detection value of the operating state detection unit 501 to 505. In addition, regarding the load state, the power conversion device 1 can detect the temperature based on the temperature, such as the detection value of the temperature sensor (not shown) of the indoor unit of the air conditioner 2, the detection value of the temperature sensor (not shown) of the outdoor unit, etc. In addition, the power conversion device 1 can also be equipped with a temperature sensor around the substrate of the inverter 310 to detect the temperature around the substrate of the inverter 310, and can also be equipped with a temperature sensor around the motor 314 to detect the temperature around the motor 314. In addition, regarding the load state, the power conversion device 1 can directly or indirectly detect the operating speed, such as the operating speed of the compressor motor, fan motor, etc. as the motor 314, based on the command value generated during the control of the control unit 400, or the estimated value estimated based on the operating frequency during the control of the control unit 400. In this way, the load state is obtained by at least one of the detection values ​​of the operating state detection units 501 to 505 that detect the operating state of the inverter 310, motor 314, etc., the instruction values ​​generated during the control process of the control unit 400, and the estimated values ​​estimated during the control process of the control unit 400.

[0098] Furthermore, the power conversion device 1 can determine the operating state of the air conditioner 2 based on the air conditioning conditions of the air conditioner 2. The air conditioning conditions of the air conditioner 2 include, for example, cooling intermediate conditions, cooling rated conditions, heating intermediate conditions, and heating rated conditions.

[0099] After the air conditioner 2 has just started to operate in the cooling action mode through user operation, the indoor temperature deviates from the set temperature. The motor 314 used in the compressor, etc. is running at a high speed, which is a state of heavy workload. Such a state represents an air-conditioning condition called a cooling rated condition, and the power consumption is high, that is, a heavy load state. At the time point when the air conditioner 2 has fully operated under the cooling rated condition, the indoor temperature is close to the set temperature. The motor 314 used in the compressor, etc. is transferred to a low speed rotation and operation, and the workload is small. Such a state represents an air-conditioning condition called a cooling intermediate condition, and the power consumption is low, that is, a low load state.

[0100] In addition, after the air conditioner 2 has just started to enter the operation of the heating action mode by the user's operation, the indoor temperature is in a state of deviation from the set temperature. The motor 314 used in the compressor, etc. is operated at a high speed, which is a state of heavy workload. Such a state represents an air-conditioning condition called the heating rated condition, and the power consumption is high, that is, it is in a heavy load state. At the time point when the air conditioner 2 fully operates under the heating rated condition, the indoor temperature is close to the set temperature. The motor 314 used in the compressor, etc. is transferred to a low-speed rotation and operates, and it becomes a state of small workload. Such a state represents an air-conditioning condition called the heating intermediate condition, and the power consumption is low, that is, it is in a low load state. In addition, regarding the air-conditioning condition of the air conditioner 2, there is an air-conditioning condition called the heating low temperature condition, which is an operation mode in an environment where the external temperature is lower than the heating rated condition. The load of the heating low temperature condition is larger than the heating rated condition, and the power consumption is in a higher state.

[0101] In this way, the waveform shape control signal output unit 420 is in light load operation when the operating state of the air conditioner 2 is the intermediate cooling condition and the intermediate heating condition, and is in heavy load operation when the operating state of the air conditioner 2 is the rated cooling condition, the rated heating condition and other air temperature conditions.

[0102] In addition, the waveform control signal output unit 420 may be configured to operate in light load mode when the difference between the external temperature and the set temperature of the air conditioner 2 is less than a specified threshold, and to operate in heavy load mode when the difference between the external temperature and the set temperature of the air conditioner 2 is greater than a specified threshold.

[0103] In addition, the waveform shape control signal output unit 420 may be in light load operation when at least one of the load current and load power output from the inverter 310 serving as a power converter is less than a prescribed threshold value, and may be in heavy load operation when at least one of the load current and load power output from the inverter 310 is greater than a prescribed threshold value.

[0104] In addition, the waveform shape control signal output unit 420 is in light load operation when at least one of the input current and input power input to the inverter 310 or converter 130 as a power converter is less than a specified threshold value, and is in heavy load operation when at least one of the input current and input power input to the inverter 310 or converter 130 as a power converter is greater than a specified threshold value.

[0105] Implementation method 5.

[0106] A description will be given of a case where an adaptive observer is applied as sensorless control of the motor 314 in the power conversion device 1 of Embodiments 1 to 4. Specifically, the description will be given by taking the power conversion device 1 of Embodiment 1 as an example.

[0107] Fig.19 1 is a diagram showing a configuration example of an air conditioner 2 according to Embodiment 5. The air conditioner 2 includes a power conversion device 1 and a motor 314 . Fig.19 The power conversion device 1 of the fifth embodiment shown is relative to Figure 1 The power conversion device 1 of the first embodiment shown in FIG. 1 is provided with a speed estimation device 101. Fig.19 In FIG. 1 , the description of the converter 130 , the inverter 310 , and the control unit 400 in the power conversion device 1 is simplified. Fig. 20 1 is a diagram showing a configuration example of a speed estimation device 101 provided in the power conversion device 1 of the air conditioner 2 according to Embodiment 5. The speed estimation device 101 estimates the rotation speed of the motor 314 using the voltage vector and the current vector applied to the motor 314 by an adaptive observer method, and obtains the estimated angular velocity ω^. r And output.

[0108] The speed estimation device 101 includes a model deviation calculation unit 11 that calculates the estimated angular velocity ω based on the voltage vector, the current vector, and the estimated angular velocity ω. r , to calculate the model deviation ε; and a first angular velocity estimation unit 21, which, based on the model deviation ε, calculates the low-frequency component of the actual angular velocity including the DC component as the first estimated angular velocity ω ^ r1 In addition, the velocity estimation device 101 includes a second angular velocity estimation unit 22 that calculates the high-frequency component of the actual angular velocity as a second estimated angular velocity ω^ based on a specific high-frequency component included in the model deviation ε. r2 And an adder 23, which is calculated by the second estimated angular velocity ω ^ r2 and the first estimated angular velocity ω r1 Add them together to calculate the estimated angular velocity ω^ r The velocity estimation device 101 is characterized in that it includes a second angular velocity estimation unit 22. The velocity estimation device 101 calculates the first estimated angular velocity ω^ r1 and the second estimated angular velocity ω r2 The added value is used as the estimated angular velocity ω r The result is fed back to the model deviation calculation unit 11 .

[0109] The model deviation calculation unit 11 includes a current estimator 12 that estimates the angular velocity ω^ based on the voltage vector, current vector, and angular velocity ω of the motor 314. r, calculating and outputting the estimated magnetic flux vector and the estimated current vector; a subtractor 13, which subtracts the current vector from the estimated current vector, calculating and outputting the current deviation vector; and a deviation calculator 14, which takes the current deviation vector as input, extracts the orthogonal component of the estimated magnetic flux vector as a scalar, and outputs the value as the model deviation ε. As a method of extracting the orthogonal component of the estimated magnetic flux vector as a scalar, there are known methods of performing coordinate transformation of the current deviation vector on two rotation axes and a method of calculating the size of the outer product value of the current deviation vector and the estimated magnetic flux vector.

[0110] The current estimator 12 estimates the current and the magnetic flux based on the state equation of the motor 314. Here, it is assumed that the motor 314 is a conventional embedded magnet type synchronous AC motor, but even if the motor 314 is other than the embedded magnet type synchronous AC motor, as long as the state equation is established, the current estimator 12 can also perform current estimation by the same method. The motor 314 other than the embedded magnet type synchronous AC motor can be exemplified by a surface magnet type synchronous motor, an induction motor, etc. In addition, in this embodiment, the rotary motor is described, but the same technology can also be applied to the direct-acting motor. This is because it can be interpreted as "the direct-acting motor is a rotary motor with an infinite rotor radius".

[0111] In this way, the air conditioner 2 can apply the adaptive observer as the sensorless control of the motor 314 .

[0112] Implementation method 6.

[0113] A case where control is performed in the power conversion device 1 of Embodiments 1 to 3 to suppress degradation of the capacitor 210 for smoothing and suppress increase in size of the device will be described. Specifically, the power conversion device 1 of Embodiment 1 will be described as an example.

[0114] Fig.21 1 is a diagram showing a configuration example of an air conditioner 2 according to Embodiment 6. The air conditioner 2 includes a power conversion device 1 and a motor 314 . Fig.21 The structure of the power conversion device 1 of the sixth embodiment shown is similar to Figure 1 The inverter 130 has the same structure as the power conversion device 1 of the illustrated embodiment 1. The inverter 130 is a rectifying unit that includes a bridge circuit composed of rectifying elements 131 to 134 and rectifies the first AC power of the power supply voltage Vs supplied from the commercial power supply 110 and outputs the rectified power.

[0115] In the present embodiment, the control unit 400 controls the operation of the inverter 310 so that the second AC power including the pulsation corresponding to the pulsation of the power flowing from the converter 130 as the rectifier to the capacitor 210 is output from the inverter 310 to the motor 314 as the load. The pulsation corresponding to the pulsation of the power flowing into the capacitor 210 is, for example, a pulsation that varies according to the frequency of the pulsation of the power flowing into the capacitor 210. Thus, the control unit 400 suppresses the current flowing through the capacitor 210. In addition, the control unit 400 may not use all the detection values ​​obtained from each detection unit, but may use a part of the detection values ​​for control.

[0116] The operation of the control unit 400 provided in the power conversion device 1 is described. In the present embodiment, in the power conversion device 1, the load generated by the inverter 310 and the motor 314 can be regarded as a constant load. When observing the current output from the capacitor 210, it is assumed that a constant current load is connected to the capacitor 210 for the following description. Here, Fig.21 As shown, the current flowing from the converter 130 is set as current I1, the current flowing to the inverter 310 is set as current I2, and the current flowing from the capacitor 210 is set as current I3. Current I2 becomes the current after the current I1 and the current I3 are combined. Current I3 can be expressed as the difference between current I2 and current I1, that is, current I2-current I1. For current I3, the discharge direction of the capacitor 210 is set as the positive direction, and the charging direction of the capacitor 210 is set as the negative direction. That is, sometimes the current flows into the capacitor 210, and sometimes the current flows out of the capacitor 210.

[0117] Fig. 22 This is a diagram showing examples of currents I1 to I3 and capacitor voltage Vdc of capacitor 210 when the current output from converter 130 is smoothed by capacitor 210 and current I2 flowing to inverter 310 becomes constant as a comparative example. Current I1, current I2, current I3, and capacitor voltage Vdc of capacitor 210 generated in response to current I3 are shown in order from the top. The vertical axis of currents I1, I2, and I3 represents current values, and the vertical axis of capacitor voltage Vdc represents voltage values. The horizontal axis represents time t in its entirety. In addition, the carrier component of inverter 310 is actually superimposed on currents I2 and I3, but this is omitted here. The same shall apply hereinafter. As Fig. 22As shown, in the power conversion device 1, it is assumed that when the current I1 flowing from the converter 130 is sufficiently smoothed by the capacitor 210, the current I2 flowing to the inverter 310 becomes a constant current value. However, a large current I3 flows in the capacitor 210, which becomes a major cause of degradation. Therefore, in the present embodiment, in the power conversion device 1, the control unit 400 controls the current I2 flowing to the inverter 310, that is, controls the operation of the inverter 310, so as to reduce the current I3 flowing to the capacitor 210.

[0118] Fig.23 This is a diagram showing an example of the currents I1 to I3 and the capacitor voltage Vdc of the capacitor 210 when the control unit 400 of the power conversion device 1 provided in the air conditioner 2 of the sixth embodiment controls the operation of the inverter 310 to reduce the current I3 flowing through the capacitor 210. From the top, the current I1, the current I2, the current I3, and the capacitor voltage Vdc of the capacitor 210 generated in response to the current I3 are shown in sequence. The vertical axis of the currents I1, I2, and I3 represents the current value, and the vertical axis of the capacitor voltage Vdc represents the voltage value. The horizontal axis represents the time t in its entirety. The control unit 400 of the power conversion device 1 controls the operation of the inverter 310 so that Fig.23 The current I2 shown flows to the inverter 310, thereby Fig. 22 Compared with the example, the frequency component of the current flowing from the converter 130 to the capacitor 210 can be reduced, and the current I3 flowing to the capacitor 210 can be reduced. Specifically, the control unit 400 controls the operation of the inverter 310 so that the current I2 including the pulsating current whose main component is the frequency component of the current I1 flows to the inverter 310.

[0119] In this way, in the power conversion device 1, the control unit 400 controls the operation of the inverter 310 as the power converter so that the pulsation corresponding to the operating state detected by the operating state detection units 501 to 505 is superimposed from the inverter 310 to the driving pattern of the motor 314 connected to the inverter 310, thereby suppressing the charging and discharging current of the capacitor 210. As a result, the air conditioner 2 can suppress the degradation of the capacitor 210 for smoothing.

[0120] Implementation method 7.

[0121] The following describes a control in which the power conversion device 1 of Embodiments 1 to 3 is controlled so that the change in DC voltage can be suppressed even when the number of switching operations of the short-circuit portion that short-circuits the commercial power supply 110 as an AC power supply is changed in accordance with the load conditions. Specifically, the power conversion device 1 of Embodiment 1 is used as an example for description.

[0122] Fig.241 is a diagram showing a configuration example of an air conditioner 2 according to Embodiment 7. The air conditioner 2 includes a power conversion device 1 and a motor 314 . Fig.24 The power conversion device 1 of the seventh embodiment shown in FIG. Figure 1 The power conversion device 1 of the illustrated embodiment 1 has the converter 130 and the capacitor 210 deleted, and has the reactor 135, the rectifier 170, and the short-circuit 30 added. The rectifier 170 includes a rectifier circuit composed of four rectifier elements 131 to 134, and a capacitor 210 connected between the output ends of the rectifier circuit and smoothing the voltage of the full-wave rectified waveform output from the rectifier circuit. The rectifier 170 rectifies the first AC power supplied from the commercial power supply 110 and outputs it.

[0123] The short-circuit section 30 short-circuits the commercial power source 110 via the reactor 135. The short-circuit section 30 includes a diode bridge 31 connected in parallel to the commercial power source 110 via the reactor 135, and a short-circuit element 32 connected to two output ends of the diode bridge 31. When the short-circuit element 32 is a metal oxide film semiconductor field effect transistor, the short-circuit element 32 has a gate connected to the control section 400, and the short-circuit element 32 is turned on and off by a drive signal from the control section 400. When the short-circuit element 32 is turned on, the commercial power source 110 is short-circuited via the reactor 135 and the diode bridge 31.

[0124] The control unit 400 controls the short-circuiting operation of the short-circuiting unit 30. The control unit 400 controls the on and off of the short-circuiting element 32 by the current open-loop control in the short-circuiting operation mode, so that the short-circuiting unit 30 is short-circuited at least twice in a half cycle of the power supply. The control unit 400 short-circuits the short-circuiting unit 30 at least twice in a half cycle of the commercial power supply 110 based on the load condition. Thus, the air conditioner 2 can suppress the variation of the DC voltage even when the number of switching of the short-circuiting unit 30 that short-circuits the commercial power supply 110 is changed in accordance with the load condition.

[0125] Implementation method 8.

[0126] Fig.25 1 is a diagram showing a configuration example of an air conditioner 900 according to Embodiment 8. The air conditioner 900 according to Embodiment 8 is used to explain the configuration of the air conditioner 2 described in Embodiment 1 in more detail. The air conditioner 900 according to Embodiment 8 may also be the air conditioner 2 described in Embodiments 2 to 7. Fig.25 In the present invention, components having the same functions as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment.

[0127] In the air conditioner 900 , the compressor 315 having the motor 314 built therein, the four-way valve 902 , the indoor heat exchanger 906 , the expansion valve 908 , and the outdoor heat exchanger 910 in Embodiment 1 are installed via a refrigerant pipe 912 .

[0128] A compression mechanism 904 for compressing the refrigerant and a motor 314 for operating the compression mechanism 904 are provided inside the compressor 315 .

[0129] The air conditioner 900 can perform heating operation or cooling operation by switching the four-way valve 902. The compression mechanism 904 is driven by a motor 314 that is subjected to variable speed control.

[0130] During heating operation, as shown by the solid arrow, the refrigerant is pressurized by the compression mechanism 904 and then sent out, and returns to the compression mechanism 904 through the four-way valve 902, the indoor heat exchanger 906, the expansion valve 908, the outdoor heat exchanger 910 and the four-way valve 902.

[0131] During cooling operation, as shown by the dotted arrow, the refrigerant is pressurized by the compression mechanism 904 and sent out, and returns to the compression mechanism 904 through the four-way valve 902, the outdoor heat exchanger 910, the expansion valve 908, the indoor heat exchanger 906 and the four-way valve 902.

[0132] During heating operation, the indoor heat exchanger 906 functions as a condenser to release heat, and the outdoor heat exchanger 910 functions as an evaporator to absorb heat. During cooling operation, the outdoor heat exchanger 910 functions as a condenser to release heat, and the indoor heat exchanger 906 functions as an evaporator to absorb heat. The expansion valve 908 decompresses the refrigerant to expand it.

[0133] Here, in the power conversion device 1 equipped with the air conditioner 900, the digital gate driver module composed of the waveform shape changer 340 and the switching elements 311a to 311f included in the inverter 310 has a larger surge voltage when the switching speed is fast, and a large amount of electromagnetic noise is generated. When the air conditioner 900 uses a refrigerant with flammability, when the refrigerant leaks, it may burn due to discharge caused by electromagnetic noise. Therefore, the air conditioner 900 sets the switching speed of the digital gate driver module equipped with the power conversion device 1 according to the flammability of the refrigerant used by the air conditioner 900. For example, the higher the flammability of the refrigerant used by the air conditioner 900, the slower the switching speed of the digital gate driver module equipped with the power conversion device 1. The air conditioner 900 can reduce the surge voltage by slowing down the switching speed of the digital gate driver module, suppress the generation of discharge caused by electromagnetic noise, and thus, it is assumed that combustion can be prevented even when the refrigerant leaks from the air conditioner 900.

[0134] The refrigerant used in the air conditioner 900 is, for example, R1234yf, R1234ze(E), R1243zf, HFO1123, HFO1132(E), R1132a, CF3I, R290, R463A, R466A, R454A, R454B, R454C, etc.

[0135] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, the embodiments may be combined with each other, and some configurations may be omitted or modified without departing from the spirit and scope of the invention.

[0136] Description of Reference Numerals

[0137] 1 power conversion device, 2, 900 air conditioner, 11 model deviation calculation unit, 12 current estimator, 13 subtractor, 14 deviation calculation unit, 21 first angular velocity estimation unit, 22 second angular velocity estimation unit, 23 adder, 30 short-circuit unit, 31 diode bridge, 32 short-circuit element, 101 velocity estimation device, 110, 110a commercial power supply, 130 inverter, 131-134, 131a-134a, 131b, 131c rectifying element, 135, 135a-135c reactor, 136, 136a-136d, 311a-311f switch Related elements, 137, 137a~137d, 312a~312f freewheeling diodes, 138 diodes, 140, 340 waveform shape changing units, 150, 350 drive circuits, 170 rectifier units, 210 capacitors, 310 inverters, 314 motors, 315 compressors, 400 control units, 410 basic pulse generating units, 420 waveform shape control signal output units, 501~505 operating status detection units, 902 four-way valves, 904 compression mechanisms, 906 indoor heat exchangers, 908 expansion valves, 910 outdoor heat exchangers, 912 refrigerant piping.

Claims

1. An air conditioner for performing air conditioning control, wherein: The air conditioner comprises: One or more switching elements included in at least one of the one or more power converters that perform power conversion; a waveform shape changing unit capable of changing the waveform shape of the switching waveform of the switching element; an operating state detecting unit for detecting an operating state of the air conditioner; as well as A waveform shape control signal output unit outputs a control signal when the switching waveform of the switching element is changed by the waveform shape change unit according to the operating state.

2. The air conditioner according to claim 1, wherein: The waveform shape changing unit divides at least one of the on-period and off-period of the switching element into two or more periods for the waveform shape of the switching waveform of the switching element based on the control signal output from the waveform shape control signal output unit, and changes the amplitude of the gate current or gate voltage of the switching element to a different size in each of the divided periods, thereby being able to change the noise and loss generated by the switching element according to the operating state.

3. The air conditioner according to claim 1 or 2, wherein: The waveform shape changing unit changes the waveform shape of the switching waveform of the switching element during rotation of at least one of a compressor motor and a fan motor included in the air conditioner.

4. The air conditioner according to claim 2, wherein: The waveform shape control signal output unit changes the waveform shape of the switching waveform of the switching element so as to suppress the loss when the operating state is a light load operation less than a specified load, and changes the waveform shape of the switching waveform of the switching element so as to suppress the noise when the operating state is a heavy load operation greater than a specified load.

5. The air conditioner according to claim 4, wherein: When the operation state is a cooling intermediate condition or a heating intermediate condition, it is the light load operation, and when the operation state is a cooling rated condition, a heating rated condition or other air temperature conditions, it is the heavy load operation.

6. The air conditioner according to claim 4, wherein: When the difference between the outside air temperature and the set temperature of the air conditioner is smaller than a predetermined threshold, the operation is performed in the light load mode. When the difference between the outside air temperature and the set temperature of the air conditioner is larger than a predetermined threshold, the operation is performed in the heavy load mode.

7. The air conditioner according to claim 4, wherein: The power converter is an inverter. When at least one of the load current and the load power output from the inverter is less than a specified threshold, it is the light load operation. When at least one of the load current and the load power output from the inverter is greater than the specified threshold, it is the heavy load operation.

8. The air conditioner according to claim 4, wherein: When at least one of the input current and the input power input to the power converter is less than a specified threshold, it is the light load operation, and when at least one of the input current and the input power input to the power converter is greater than a specified threshold, it is the heavy load operation.

9. The air conditioner according to any one of claims 1 to 8, wherein: The power converter including the switching element further includes the waveform shape changing unit. The power converter is an inverter, or a converter, or an inverter and a converter.

10. The air conditioner according to any one of claims 1 to 9, wherein: The air conditioner is provided with a speed estimation device. The speed estimation device comprises: a model deviation calculation unit that calculates a model deviation based on a voltage, a current, and an estimated angular velocity of the AC motor; a first angular velocity estimation unit that calculates a low-frequency component including a DC component of the actual angular velocity as a first estimated angular velocity based on the model deviation; a second angular velocity estimating unit that calculates a high-frequency component of the actual angular velocity as a second estimated angular velocity based on a specific high-frequency component included in the model deviation; as well as an adder that adds the first estimated angular velocity and the second estimated angular velocity, An added value of the first estimated angular velocity and the second estimated angular velocity is fed back to the model deviation calculation unit as the estimated angular velocity.

11. The air conditioner according to any one of claims 1 to 9, wherein: The air conditioner comprises: a rectifier that rectifies AC power supplied from a commercial power source; a capacitor connected to an output terminal of the rectifying unit; and A control unit, which includes the waveform shape control signal output unit, controls the operation of the inverter as the power converter, so that the pulsation corresponding to the operating state detected by the operating state detection unit is superimposed from the inverter to the driving pattern of the motor connected to the inverter, thereby suppressing the charging and discharging current of the capacitor.

12. The air conditioner according to any one of claims 1 to 9, wherein: The air conditioner comprises: a rectifier that rectifies AC power supplied from a commercial power source; a short-circuiting section that short-circuits the commercial power supply via a reactor; and A control unit, which includes the waveform shape control signal output unit, controls the short-circuiting action of the short-circuiting unit, The control unit short-circuits the short-circuit unit at least twice within a half cycle of the commercial power supply based on a load condition.

13. The air conditioner according to any one of claims 1 to 12, wherein: The refrigerant used is any of R1234yf, R1234ze(E), R1243zf, HFO1123, HFO1132(E), R1132a, CF3I, R290, R463A, R466A, R454A, R454B, and R454C.

14. The air conditioner according to claim 13, wherein: A switching speed of a digital gate driver module included in the air conditioner is set according to the combustibility of the refrigerant.

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